Carboxyalkylmercaptomethyl siloxanes



United States Patent 6 ABSTRACT OF THE DISCLOSURE A novel class ofcarbofunctional organopolysiloxanes is disclosed, the same beingsuitable for use as levelling agents for polyester lacquers, aslubricants and as additives for water soluble or emulsifiable drillingand cutting oils. The carbofunctional organo-polysiloxanes correspond tothe formula RnSiO wherein n has a value greater than 1 but not exceeding3, at least one of the siloxane units is a mercaptomethylsiloxane unithaving the following formula r O1 2SiOH2-SCHr CH CHa-O-C-R R Lani, (l

and each substituent R of all remaining siloxane units is alkyl or aryl,in the said mercaptomethybsiloxane units R is CH or R" is H or C RIII isacyl which is derived from a monoor poly-basic saturated or unsaturatedaliphatic, cycloaliphatic or aromatic carboxylic acid, or carbonic acid.

In is either 0 or 1, and

The invention relates to novel carbofunctional organopolysiloxanecompounds and a process for the production thereof.

These compounds have the average formula Rn SiO wherein the number n isgreater than 1 and at most equal to 3, at least one of the substituentsR is a carboxyalkylmercaptomethyl radical more closely defined in thefollowing, and all other substituents R- are alkyl or aryl radicalsincluding indiiferently substituted alkyl or aryl radicals, preferablymethyl radicals alone, or methyl and phenyl radicals. In theseorgano-polysiloxanes according to the invention thecarboxyalkylrnercaptomethyl-substituted siloxane units correspond to thegeneral formula In this formula,

ice

is an acyl radical which derives from a monoor polybasic, optionallyindiiferently substituted, saturated or unsaturated, aliphatic,cycloaliphatic or aromatic carboxylic acid, including carbonic acid, andwhich in relation to the other acid functions may be free, chlorinated,or esterified with a monoor poly-hydric aliphatic alcohol, apolyalkylene glycol, a polyalkylene glycol monoalkyl ether or ahydroxyalkylmercaptornethyl siloxane unit of the foregoing structure.

The aforesaid new esterified organosiloxanes are very useful surfaceactive additives; more particularly, they are applicable as levellingagents, especially for polyester lacquers, and as lubricants, especiallyas additives for Water-soluble or water-emulsifiable drilling andcutting oils.

For the manufacture of the products described above, according to thepresent invention a [i-hydroxyethylmercaptomethyl siloxane or a [3-,'y-dihydroxypropylmercaptomethyl siloxane is reacted with the chlorideor anhydride of a carboxylic acid which may be monoor poly-basic,saturated or unsaturated aliphatic, cycloaliphatic or aromatic,including indifferently substituted carboxylic acids, and optionallywith a monoor poly-hydric aliphatic alcohol, a polyalkylene glycol or apolyalkylene glycol monoalkyl ether, at a temperature between 10 and C.in the presence of a tertiary nitrogen base, for example pyridine ortriethylamine. Inert solvents, especially benzene or toluene, can beused in addition. In the case of sufficiently reactive acid anhydrides,the addition of a nitrogen base may be dispensed with.

The hydroxyalkylmercaptomethyl siloxanes used in the process justdescribed have the average formula XDSiO In this formula the number n isgreater than 1 and at most equal to 3. At least one of the siloxaneunits of these polysiloxanes has the formula R LAHJ,

wherein R'=CH or 0 and m*=0 or 1. In all other siloxane units thesubstituents X are alkyl or aryl radicals including inditferentlysubstituted alkyl or aryl radicals, preferably methyl radicals alone, ormethyl and phenyl radicals.

Polysiloxanes of this type are obtained, for example, by reactingbromomethyl-substituted silanes or siloxanes withB-hydroxyethylrnercaptan or l-thioglycerol, as described in more detailin US. patent application Serial Numbers 286,909 and 329,875, filed June11, 1963, by Simmler and Niederpriim, and December 11, 1963, by Simmler,Niederpriirn, and I onas, respectively.

As examples of the acyl chlorides and acid anhydrides the following maybe mentioned: phosgene, acetyl chloride, monochloroacetyl chloride,propionyl chloride, isovaleryl chloride, stearic acid chloride,methacrylic acid chloride, oleic acid chloride, oxalyl chloride,succinyl chloride, benzoyl chloride, 4-chlorobenzoyl chloride, 4-methoxybenzoyl chloride, 3,5-dinitrobenzoyl chloride, pto-luic aci-dchloride, 4-nitrophenylacetyl chloride, phthalyl chloride, terephthalylchloride, anthraquinonecarboxylic acid-(2)-chloride; acetic anhydride,methoxyaceticanhydricle, propionic acid anhydride, succinic acidanhydride, maleic acid anhydride, tetrapropenylsuccinic acid anhydride,hexahydropthalic acid anhydride, 1,2,3,6-tetrahydrophthalic acidanhydride, benzoic acid anhydride, is continued for 2 hours. Theprecipitated pyridinium chlophthalic acid anhydride, tetrachlorophthalicacid anhyride is then separated by filtration, the solvent is evapdride,benzenetetracarboxylic acid-(1,2,4,5)-anhydride orated from the filtrateby heating at 1 mm. Hg at 80 C., and naphthalene-dicarboxylicacid-(1,8)-anhydride. and the residue is again filtered. A clear,colourless oil is The amounts of the reactants may be chosen in such a 5obtained as filtrate of which the infra-red and the nuclear proportionthat the number of hydroxyl groups contained magnetic resonance spectraare the same as those of the in the hydroxyalkylmercaptomethyl siloxaneequals the product of Example 1. At C. its density is 1.025 number ofacyl radicals contained in the carboxylic acid g./cm. its viscosity 34.5cp. and its refractive index derivative, or that the one or the other ispresent in exn =l.4293. gessdlscot that part thereof remains unalteredin the end 10 Example 3 The following examples are given for the purposeof 207 grams of a tris-(B,' -dihydroxy-n-propylmercaptoillustrating theinvention, the percentages are percent by methyl)-polymethyl siloxanewhich, with a 4.1% hydroxyl weight. content, corresponds approximatelyto the formula 50 g. pyridine and 78 g. (0.6 mol) propionic acidanhydride, and the mixture is heated at boiling temperature under refluxfor 2 hours. The solvent is then evaporated by heating u to 80 C. at 1mm. Hg and the OlSKCHmROW SKCHQFCHPSrCHPCHPOH residue is filtered. Thefiltrate is a yellowish oil of saponi- 320 grams of atris-(fi-hydroxyethylmercaptomethyl)- polymethyl siloxane which, with a2.9% hydroxyl content, corresponds approximately to the formula L J5fication value 124, containing 3.5% sulphur. At 20 C. its density is1.035 g./cm. its viscosity 76.6 cp. and its HC-Si0T-Sl(CHs)2Oj-Si(CHa)lCH2S-CH2CHa-OH refractive index n =1.4283.

F Example 4 OTSKCHQPOISKCHH) CHQ*S"CH OHPOH 494 grams of an a,w-bis(8'-hydroxyethylmercaptomethyl)-polydimethyl siloxane which, with a 2.8%hyis mixed with 300 cm. anhydrous toluene and 67 g. acetic droxylcontent, corresponds approximately to the formula (3H [(13111 I ([311;HO'CHQCHE S' CH2 fiiOfilO-?iCH2 SCH2CHT OH CH3 LCHa .112 CH:

anhydride, and the mixture is heated at boiling temperacontaining 0.814mol OH, is mixed with 500 cm. anhyture under reflux for 5 hours. Thesolvent is then evapordrous benzene and 77 g. (0.976 mol) pyridine (20%ex- .ated by heating at 2 mm. Hg at 90 C., and the residue cess). Themixture is reacted with a solution of 52 g. is filtered. A clear, almostcolourless oil results as filtrate, (0.407 mol) oxalyl chloride in 200cm? benzene in a which contains 5% S and 5.3% CH CO. At 20 C. its manneranalogous to that described in Example and density is 1.025 g./cm. itsviscosity 30.4 cp. and its rethe further procedure there described isfollowed. A f ti i de =1 4293 vicous oil is obtained of saponificationvalue 86, containing 4.8% sulphur. At 20 the density is 1.035 g./crn.Example 2 its viscosity 1767 cp. and its refractive index n :1.4343. 315grams of a tris-(B-hydroxyethylmercaptomethyl) Example 5 polymethylslloxane which, with a 2.7% hydroxyl con- 2 grams of the Samepolysiloxane as employed in tent, corresponds approximately to the frmula! Example 4, containing 0.4 mol OH, is mixed with 300 F j cm.toluene and 48 g. (0.48 mol) succinic acid anhydride OTS(CH)2 OIs(CH3)CH' S CHZCHZ OH and the mixture is heated at boiling temperature underreflux for 5 hours. The solvent is then evaporated by heat- 1 mg up to100 C. at 200 mm. Hg and the residue is L J6 filtered. The filtrate is aviscous oil of saponification value 149 and acid number 78, whichcontains 4.7% sulphur. OTsl(CH3(2 OTSl(GHK)Q-CHZSCHTCHQOH At 20 C. itsdensity is 1.055 g./cm. its viscosity 206 5 cp. and its refractive indexn =1.4365.

containing 0.5 mol OH, is mixed with 300 cm. anhydrous Example 6 benzeneand 39.5 g. (0.5 mol) pyridine. A solution of 39 405 grams of ana,w-bis-( 3'-hydroxyethylmercaptog. (0.5 mol) acetyl chloride in 100 cm.benzene is added methyD-polydimethyl siloxane which, with a 2.1%hydropwise with stirring at room temperature and stirring 70 droxylcontent, corresponds approximately to the formula l Ll CH3 CH3 18 CH3containing 0.5 mol OH, is mixed with 400 cm. benzene and 39 g. pyridine.The mixture is reacted with a solution of 31 g. (0.2 mol) succinylchloride in 100 cm? benzene in a manner analogous to that described inExample 2 and the further procedure followed as there described. Aviscous oil results, of saponification value 60, which contains 4%sulphur and less than 0.1% of hydroxyl groups. At 20 C. its density is1.025 g./cm. its viscosity 582 cp. and its refractive index n =1.4285.

Example 7 315 grams of the same polysiloxane as that employed in Example2, containing 0.5 mol OH, is mixed with 300 cm. benzene and 39 g.pyridine. The mixture is reacted with a solution of 52 g. (0.5 mol)methacrylic acid chloride in 100 cm. benzene in a manner analogous tothat described in Example 2, and the further procedure is the same asthat there described. A clear oil is obtained of saponification value81, which contains 4.8% sulphur. At 20 C. its density is 1.02 g./cm. itsviscosity 45 cp. and its refractive index n =1.43 68.

Example 8 43 grams of the same polysiloxane as that employed in Example4, containing 0.4 mol OH, is mixed with 300 cm. toluene and 47 g. (0.48mol) maleic acid anhydride, and the further procedure is the same asthat of Example 1. A viscous oil of acid number 58 results whichcontains 4.9% sulphur. At 20'' C. its density is 1.05 g./cm. itsviscosity 476 cp. and its refractive index n =1.4391.

Example 9 315 grams of the same polysiloxane as that employed in Example2 containing 0.5 mol OH, is mixed with 300 cm. benzene and 39 g.pyridine. The mixture is reacted with a solution of 70 g. (0.5 mol)benzoyl chloride in 100 cm. benzene in the manner analogous to thatdescribed in Example 2, and the further procedure there described isfollowed. A clear oil is obtained of saponi fication value 82, whichcontains 4.7% sulphur. At 20 C. its density is 1.045 g./cm. itsviscosity 63.7 cp. and its refractive index n =1.4530.

Example 10 252 grams of the same polysiloxane as that employed inExample 2, containing 0.4 mol OH, are mixed with 400 cm. toluene and 60g. (0.4 mol) phthalic acid anhydride and the further procedure ofExample 1 is followed. The product is a viscous oil of saponificationvalue 149 and acid number 65 (hydroxyl number=0), which contains 4.5%sulphur. At 20 C. its density is 1.075 g./cm. its viscosity 542 cp. andits refractive index n =1.4575.

Example 1] 405 grams of the same polysiloxane as that employed inExample 6, containing 0.5 mol OH, is mixed with 400 cm. benzene and 39g. pyridine. The mixture is reacted with a solution of 41 g. (0.2 mol)terephthalic acid chloride in 100 cm. benzene in a manner analogous tothat of Example 2 and the further procedure there described is followed.A viscous oil results of saponification value 55, which contains 3.6%sulphur and 0.2% terminal hydroxyl groups. At 20 C. its density is 1.02g./cm. its viscosity 870 cp. and its refractive index n =1.4372.

Example 12 370 grams of a tris-(B-hydroxyethylmercaptomethyl)-polymethyl siloxane which, with a 2.3% hydroxy content, correspondsapproximately to the formula containing 0.5 mol OH, is mixed with 1400cm. benzene, g. 1.2 mol) pyridine and 773 g. of an anhydrouspolyalkylene glycol mono-n-butyl ether containing 1.1% bydroxyl groups,i.e. altogether likewise 0.5 mol OH, the oxyalkylene chain being for-medin equal parts by weight from ethylene oxide and propylene oxide. Themixture is reacted with a solution of 70 g. (0.55 mol) oxalyl chloridein 300 cm. benzene in a manner analogous to that described in Example 2,and the further procedure there described is followed. A viscous oil isobtained of saponification value 52, containing 8.7% Si and 1.5% S. At20 C. its density is 1.06 g./cm. its viscosity 2500 cp. and itsrefractive index n 1.4515.

What is claimed is:

1. A carbofunctional organo-polysiloxane compound of the average formulawherein n is a number greater than 1 and at most equal to 3, at leastone of the siloxane units is a mercaptomethylsiloxane unit having theformula E O1/zSi-OHzSCHg CH CH2-OCR and each substituent R of allremaining siloxane units is a radical selected from the group consistingof alkyl, aryl,

.indifierently substituted alkyl and indifierently substituted aryl, inthe said mercaptomethyl-siloxane units R being a member selected fromthe group consisting of CH and 0 R being a member selected from thegroup consisting of H and C RIII rtnsio wherein n is a number greaterthan 1 and at most equal to 3, at least one of the siloxane units is amercaptomethylsiloxane unit having the formula and each substituent R ofall remaining siloxane units is a radical selected from the groupconsisting of alkyl, aryl, indifferently substituted alkyl andindifferently substituted aryl, in the said mercaptomethylsiloxane unitsR being a member selected from the group consisting of CH and 0 R" beinga member selected from the group con- 'sisting of H and in being anumber selected from the group consisting of 0 and 1, and

being an acyl radical which is derived from a carboxylic acid selectedfrom the group consisting of poly-basic saturated and unsaturatedaliphatic, cycloaliphatic and aromatic carboxylic acids, and carbonicacid, at least one of the carboxy groups of the said carboxylic acidbeing substituted by a member selected from the group consisting ofchlorine and ester radicals of monoand poly-hydric aliphatic alcohols,polyalkylene glycols, poly-alkylene glycol monoalkyl ethers andhydroxyakylmercaptomethyl siloxane units of the foregoing definedstructure.

References Cited UNITED STATES PATENTS 2,947,772 8/1960 Eynon et a1260448.2 X

8 FOREIGN PATENTS 1,378,592 12/1963 France.

OTHER REFERENCES 5 Noller, Chemistry of Organic Compounds, 2nd edition,pp. 152, 161, 163, W. B. Saunders Co., Philadelphia (1957).

HELEN M. MCCARTHY, Primary Examiner.

10 TOBIAS E. L'EVOW, Examiner.

P. F. SHAVER, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,370,076 February 20, 1968 Hans Niederpriim et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 2, line 71, "hexahydropthalic" should read hexahydrophthalicColumn 4, line 52, "vicous" should read viscous line 53, "20" shouldread 20 C. line 61 "200 mm." should read 20 Column 5, line 23, "43grams" should read 243 grams Column 7, line 6,"hydroxyakylmercaptomethyl" should read hydroxyalkylmercaptomethylSigned and sealed this 19th day of August 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents

